[13C]valine metabolism in methylmalonicacidemia using nuclear magnetic resonance: propionate as an obligate intermediate

K. Tanaka, Ian M Armitage, H. S. Ramsdell

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13C] and [α,β 13C]valine were administered sequentially to a patient with methylmalonicacidemia to clarify the metabolic pathway of valine from methylmalonic acid semialdehyde to methylmalonyl CoA. Methylmalonic acid was isolated from multiple urine samples, purified, and analyzed by 13C nuclear magnetic resonance spectroscopy. Contrary to the widely accepted view, the results show unequivocally that methylmalonic acid semialdehyde is decarboxylated to propionate before conversion to methylmalonyl CoA.

Original languageEnglish (US)
Pages (from-to)3692-3696
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number9
StatePublished - Jan 1 1975
Externally publishedYes


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